Weft compressing motion for circular looms



Feb. 18, 1958 J. RABEUX ETAL 2 WEFT COMPRESSING MOTION FOR CIRCULAR Looms Filed Nov; 4, 1953 2 Sheets-Sheet 1 Feb. 18, 1958 J. RABEUX ETAL 2,823,704

WEFT COMPRESSING MOTION FOR CIRCULAR LOOMS Filed Nov. 4, 1955 2-Sheets-Sheet 2 INVENTORS.

United States Patent WEFT COMPRESSING MOTION FOR CIRCULAR LOOMS Jean Rabeux, Paris, and Bernard Masson, Courbevoie, France, assignors to Societe dApplications Gencrales dElectricite & de Mecanique, Paris, France Application November 4, 1953, Serial No. 390,198 Claims priority, application France November 10, 1952 10 Claims. (Cl. 139-433) This invention relates to looms, and more particularly to a weft compressing motion for looms especially circular looms.

In hitherto known looms it is customary to use wheels, freely rotatable on their shafts, for compressing the weft. Said wheels are rotated by engagement with the warp threads when the latter move jointly with the shuttles.

Said wheels arranged outside the shed above or below the sheets of warp threads are in engagement with the latter by means of elements arranged at their circumference. Said elements may be of different shape; for example, said wheels may be provided with teeth, with needles or with recesses.

The hitherto known weft compressing motions, however, have many disadvantages. For example, they may cause damage to the weft threads and the warp threads which even may lead to thread breakage. Moreover, especially when wheels with needles are used, they may cause injuries to the operator of the loom.

An object of the present invention is to provide a weft compressing motion for looms by means of which the disadvantages of the hitherto known weft compressing motions are overcome.

Another object of the invention is to improve on the art of weft compressing motions for looms as now ordinarily made.

Other objects and structural details of the invention will be apparent from the following description when read in conjunction with the accompanying drawings forming part of this specification, wherein:

Fig. la is a fragmentary and somewhat diagrammatical side elevational view of a weft compressing motion according to the invention,

Fig. 1b is a perspective view of the motion shown in Fig. la,

Fig. 1c is a top plan view of the motion shown in Fig. la,

Figs. 2a and 2b illustrate an arrangement of a weft compressing motion according to the invention in a circular loom with a horizontal shed,

Figs. 3a and 3b illustrate another arrangement of a weft compressing motion according to the invention in a circular loom with a vertical shed.

Figs. 4a and 4b illustrate a different arrangement of a weft compressing motion according to the invention in a circular loom having a horizontal shed, and

Figs. 5a and 5b illustrate a further arrangement of a weft compressing motion according to the invention in a circular loom having a vertical shed.

Referring now to Figs. la, 1b, and 1c, 1 generally indicates a wheel or disk of a weft compressing motion of a loom according to the invention. A series of curved blades or tongues 2 having flat cross-section is arranged in the circumference of the wheel 1. The blades 2 are of a special shape, so that, after compressing the Weft 7 at the bottom of the shed, said blades 2 move away r" I, 2,823,704 Ice Patented Feb.'18, 1958 from the sheet of warp threads in a rational geometric way.

Upon moving away from the sheets, the blade 2 does not have the tendency to stoick to the warp threads or to the laid weft thread whereby a damage to the threads or a breakage thereof could occur. Therefore, it is no longer necessary to provide for a sliding of the threads along the active surface of the blade so as to pass above the latter whereby the effectiveness of the weft compressing motion is reduced.

Thus, the blade 2 acts as a profile of a gearing tooth with respect to the warp threads playing the role of a rack; furthermore, in order to obtain above described conditions, it is necessary that the tangent T to the active edge of the blade 2 at its point 3 of contact with the weft thread 7 is always perpendicular to the mean plane 4 of the shed in case of a loom with a horizontal shed or, in case of a loom with a vertical shed, is perpendicular to the plane tangent to the point of the cylinder formed by the axes of the successive sheds of all warp threads.

These conditions are obtained, for example, by at least approximately giving the active edge of the blade 2 the shape of a predetermined involute of a circle as indicated in Fig. 1a for a circular loom having a horizontal shed.

Thus, the blade 2 has the shape of the rolling off surface of a tooth of an involute gearing, the other characteristics of such a tooth being determined by the angular position of the wheel (see Figs. 1b and 10).

Furthermore, the blade 2 has an inclined edge 5 at its inactive side. Moreover, the extreme end 6 is rounded in a suitable manner.

Blade wheels of above described type according to the invention have the following advantages:

The weft compressing wheel may be readily manu factured.

While hitherto customary needles on weft compressing wheels are subject to twisting, breaking and loosing their points during a weaving operation, i. e. hardly noticeable features which may cause breakage of the warp, this is not so with the blades according to the invention as the latter are sturdy and little fragile. Therefore, the blades according to the invention eliminate breakage of yarn the cause of which often cannot be determined immediately in looms having the hitherto customary weft compressing wheels.

The rounded edges of the blades according to the invention prevent injuries to the hands of the operator; also they prevent damage to the warp threads when the blades enter into the sheets.

As the blades leave the sheets in a rational way, they will not cause a deterioration of the warp threads and the weft threads. Therefore, the blades may be made much longer than, or may be used along a much greater length than the hitherto customary elements, such as needles,

teeth, etc. With such customary elements it becomes necessary, especially for high settings, to lift the sheet of Warp threads so as to give the wheel a sufficient zone of action.

The hitherto customary teeth used for the compressed settings become so small in effect that the action of the wheel would be almost zero if it would not lift the sheet to a considerable degree. The conditions are quite similar for the hitherto customary straight needles, as it is necessary to use comparatively short needles so as to avoid damage to the warp threads when the needles leave the sheets.

The blade wheels according to the invention are in engagement with the sheets only by means of their blades; the warp threads are not displaced from their normal positions through the rim of the blade wheels. Yet, a considerable zone of action may be obtained. by a blade 3 wheel according toth'e invention. A significant fatigue on.the.warp.threads is alsoavoided.

As the blades according to the invention are very rigid owing to their form and their mode of operation is rational, an energetic compression, more efii'cient than obtainable by the hitherto customary Weft compressing motions, is assured.

A blade wheel according: to the invention'may be de signed and arranged in the loom in such a manner that it may. be used at an angle most suitable for its operation.

and being determined by the condition that the tangent to said curve drawn from the point of contact with a weft thread is always perpendicular to the mean plane of the shed wherein the warp threads are generally located at the moment of compression.

2. In a weft compressing motion as claimed in claim I, the end of said blades having an inclined edge at its inactive side.

(1) The axis of the wheel intersects the axis of the loom (for example a-circular loom) and forms with said axis of the loom an angle. which is variable between and 90. Thisarrangementprovides for a helicoidal engagement between the blade wheel and the warp.

(a) Figs. 2a and 2b illustrate this arrangement for a circular. loom having a horizontal shed 104. The axis 110 of the blade wheel. 101 is at an angle A to the axis 112 of the circular loom.

(b) Figs. 3a and 3b illustrate this arrangement for a circular loom having a vertical. shed 204. The axis 210 of the blade wheel 201 is at an angle A to the axis 212 of the circular loom.

(2) The axis ofv the blade wheel does not intersect the'axis of the loom. This arrangement provides for a conical engagement between the blade wheel and the warp.

(a) Figs. 4a and 4b illustrate this'arrangement for a circular loom having a horizontal shed 304. The axis 310 of the blade wheel 301 is in a plane perpendicular to the plane of the axis 312 of the loom.

(b) Figs. 5a and 5b illustrate this arrangement for a circular. loom havinga vertical shed 404. The axis 410 of the blade wheel 401 is in a plane parallel to the axis 412 of the; loom.

Above describedFigs. 1a, 1b and 1c illustrating constructional' details of the blade Wheel show an arrangement of the latter in accordance with the angular position of the blade wheelaccording to Figs. 5a and 5b.

(3) The characteristics of the angular position of the blade wheel, mentioned under 1 and 2 above are combined, for example as shown in the U. S. Patent 1,465,445 issued May 18, 1918, or the blade which is mounted on a universal support. This arrangement provides for a conical. engagement of the Gleason type between the blade wheel and the. warp.

We have described preferred embodiments of our invention, but it is understood that this disclosure is for thepurpose of illustration and that various omissions or changes in shape, proportion and arrangement of parts, as well as the substitution of equivalent elements for those, herein shown and described may be made without departing from the spirit and scope of the invention as set :forth in the appended claims.

What we claim is:

1. A weft compressing motion for circular looms having a horizontal shed comprising in combination: a m tatable wheel, and. a. series. of curved blades having flat cross-sections arranged radially on the circumference of saidwheel, the active edge of each blade being curved 3. In a weft compressing motion as claimed in claim 1, the extreme end. of said blades having a rounded edge.

4. In a weft compressing motion as claimed in claim 1, said wheel being arranged at a distance from the sheets of Warp threads suchias' always to leave a space between said threads and the wheel rim.

5. A weft compressing motion for circular looms having a verticalshed, comprising in combination: a rotatable wheel, and a series of curved blades having flat crosssections arranged radially on the circumference of said wheel, the active edge of each blade'being curved and determined bythe condition that the tangent to said curve drawn from the point of contact with a weft thread is always perpendicular to the mean plane of the shed.

6. In a weftcompressing motion as claimed in claim 5, the end of said blades having an inclined edge at its inactive side.

7. In a weft compressing motion as claimed in claim 5, the extreme endof said blades having a rounded edge.

8. In a weft compressing motion as claimed in claim 5, said wheel being arranged at a distance from the sheets of warp threads such as always to leave a space between said threads and the wheel rim.

9. In a weaving loom having a horizontal shed a device for. compressing the weft threads including a rotatable wheel and a series of curved blades having fiat cross-sections of substantially constant width arranged on the circumference ofisaidwheel the active edge of each blade being adapted. for making contact with a weft thread and being: curved such as to at least approximate a curve being determined. by the condition that the tangent to said curve drawn from the point of contact with a weft thread is always perpendicular to the mean plane of the shed wherein the warp threads are generally located at the moment of compression.

10. A weft compressing motion for a circular loom having a shed comprising a rotatable wheel, and a'series of curved bladeshaving fiatcross-sections arranged radially on the circumference of said wheel, the active edge of each blade being curved and'determined by the condition that? the tangent to said curve drawn from the point of contact with a weft thread always lies in a radial plane containing the loom axis and is perpendicular to the nearest warp thread with the shed closed.

References Cited inthe file of this patent UNITED STATES PATENTS 2,398,956 Pelce Apr. 23, 1946 2,528,172" Pelee Oct. 31, 1950 FOREIGN PATENTS 67;8-59- Netherlands May 15, 1951 503,230 Belgium May 31, 1951 

